84 Scientific Proceedings, Royal Ihihlin Society. 



(5) The corona loss is nil, as the disniptive ciitical voltage exceeds the operating 

 voltage. 



Owing to the poor efficiency and bad regulation, it would be better to redesign 

 the line for a higher voltage. 



IG. Using the approximate method of paragraph 12 for the example of the last 

 paragraph, we obtain the following results : — 



V{- = (38,000;x -85 + 85 X -34 x 200)2 + (38,000 x -527 + 85 x '648 x 200)2 

 = (32,300 4 5,780)2 + (20,000 + U.OOOy^ = 2-411 x 10»- 

 .-. Fj = 49,100. 



" = ^— ko = ■'''■ ^ 



^ 32300 

 49,100 

 P-' = 38;000 = ^ ^^- 

 Comparing these results with those of paragraph 15, we find : — 



Par. 15 Par. 16 



Voltage to neutral at sending end, 46,750 49,100 



Efficiency at greatest load, '876 '849 



Eegulation fraction, 1-305 1-29 



These results are somewhat discordant, and consec^uently the more accurate 

 method of paragraph 15 is preferable here, except for a rough approximation. 



17. Data as in paragraph 15, but let voltage between wires at receiving end 

 be 100,000 volts, and spacing between conductors be 120 inches. 



(2) Por the same power delivered, the effective mean current is now 



C = 31 X -— = 20-5 amps. 



The most economic size is then 



A' = -00392 X 20-5 = -0805 sq. inch. 

 Choose conductor 19/14, having A = -097 sq. inch, and a = 0-20 inch. 



(3) Calculation of line constants. 



R .. -'4 - -45. 

 A 



a = -2, 5 = 120. 



- = 600, log,„- -■=■■ 2-78. 

 a a 



Z = (8 + 74-1 X 2-78) X 10- = 2-14 x 10-'. 

 K= bx 10-». 



..?2|ii?::.,.395«io-., 



